The Annotated Art of War (Parts 11.15-19: Division, Moves and Speed)

XI. The Nine Situations

Sun Tzu said:

Commentary

15. Those who were called skillful leaders of old knew how to drive a wedge
between the enemy's front and rear; to prevent co-operation between his large
and small divisions; to hinder the good troops from rescuing the bad, the
officers from rallying their men.

The
wedge is a classic tactic for
breaking a defensive line. Like a nail penetrating a hard wood, a
focused force can break through a strong defense. In physics,
pressure is measured as force per unit area. This means a small
force at a single point can still cause tremendous pressure. In war
it is sometimes called 'divide and conquer'.

A wedge from the side
isolates the front-line troops from the rearguard, making each more
vulnerable.

The wedge can also be used in business, for example in breaking
up competitive alliances.

16. When the enemy's men were united, they managed to keep them in disorder.

Unity and order are
closely related. Hence if you divide their forces they will be
inclined to disorder.

One reason for this is that you may well be
able to separate men from their commanders. Thus isolated, they will
become like headless chickens.

17. When it was to their advantage, they made a forward move; when otherwise,
they stopped still.

War is not just about
advancing. It is about being in the place of greatest potential and
advantage.

This principle can result in movement in any direction, including
going backwards or remaining still.

18. If asked how to cope with a great host of the enemy in orderly array and
on the point of marching to the attack, I should say: "Begin by seizing
something which your opponent holds dear; then he will be amenable to your
will."

Something that is
'held dear' implies an emotional attachment. When a person is
attached to something, they make it a part of their
identity.
their self. Taking the attached thing is like stealing a part of
their self. It feels like the basest abuse and creates anger, fear,
loss and other strong emotions.

In war this may be a beautiful
city, a famed person, critical armaments and more.

Greater than the sense of temporary loss is the fear that the
taken item will be destroyed, leading to permanent loss and hence
extinction of a part of the person. This threat can wean away any
anger and lead to fearful compliance.

19. Rapidity is the essence of war: take advantage of the enemy's
unreadiness, make your way by unexpected routes, and attack unguarded spots.

War is a game of
positioning. Where you are at any time is critical. In between, as
you travel to these places, you are vulnerable. Speed hence reduces
the chance of dangerous attack.

Getting to strong positions
earlier than the enemy expects also gives you the advantage of
surprise and hence letting you attack them where they are weak.

Speed also lets you travel in circuitous routes to avoid
detection and yet arrive in time.

Finally, speed gives you kinetic energy, which in physics is
measured as half of the mass times the speed squared. An
attack at speed hence is very powerful.